Nickel compositions for preparing nickel metal and nickel complexes

ABSTRACT

Nickel compositions for use in manufacturing nickel metal compositions, and specifically to methods of making basic nickel carbonates used to produce nickel metal compositions are disclosed. By varying the molar ratios of carbonates and bicarbonates to nickel salts, the methods provide basic nickel carbonates that produce superior nickel-containing solids that react more effectively with phosphorous-containing ligands. The phosphorous containing ligands can be both monodentate and bidentate phosphorous-containing ligands.

RELATED APPLICATIONS

This application claims benefit to U.S. Provisional application No.61/287,757 filed on Dec. 18, 2009 and U.S. Provisional application No.61/380,445 filed on Sep. 7, 2010, both herein incorporated by referencein their entirety.

FIELD OF THE INVENTION

The invention relates to nickel compositions for use in manufacturingnickel metal compositions, and specifically to methods of making basicnickel carbonates (BNC) used to produce nickel metal compositions. Thenickel metal compositions can be used to produce nickel catalystcomplexes with phosphorous-containing ligands.

BACKGROUND OF THE TECHNOLOGY

Hydrocyanation catalyst systems, particularly pertaining to thehydrocyanation of ethylenically unsaturated compounds, are known in theart. For example, systems useful for the hydrocyanation of 1,3-butadiene(BD) to form pentenenitrile (PN) and in the subsequent hydrocyanation ofpentenenitrile to form adiponitrile (ADN) are known in the commerciallyimportant nylon synthesis field.

The hydrocyanation of ethylenically unsaturated compounds usingtransition metal complexes with monodentate phosphite ligands isdocumented in the prior art. See, for example, U.S. Pat. Nos. 3,496,215;3,631,191; 3,655,723 and 3,766,237, and Tolman et al., Advances inCatalysis, 1985, 33, 1. The hydrocyanation of activated ethylenicallyunsaturated compounds, such as with conjugated ethylenically unsaturatedcompounds (e.g., BD and styrene), and strained ethylenically unsaturatedcompounds (e.g., norbornene) proceeds without the use of a Lewis acidpromoter, while hydrocyanation of unactivated ethylenically unsaturatedcompounds, such as 1-octene and 3-pentenenitrile (3PN), requires the useof a Lewis acid promoter. Recently, catalyst compositions and processesfor the hydrocyanation of monoethylenically unsaturated compounds usingzero-valent nickel and bidentate phosphite ligands in the presence ofLewis acid promoters have been described; for example in U.S. Pat. Nos.5,512,696; 5,723,641 and 6,171,996.

U.S. Pat. No. 3,903,120 describes the preparation of zerovalent nickelcomplexes of the types Ni(MZ₃)₄ and Ni(MZ₃)₂A; wherein M is P, As or Sb;Z is R or OR, wherein R is an alkyl or aryl radical having up to 18carbon atoms and may be the same or different, and at least one Z is OR;A is a monoolefinic compound having 2 to 20 carbon atoms; the R radicalsof a given MZ₃ of Ni(MZ₃)₂A preferably being so chosen that the ligandhas a cone angle of at least 130°; are prepared by reacting elementalnickel with the monodentate MZ₃ ligand at a temperature in the range of0° C.-150° C. in the presence of a halogen-containing derivative of themonodentate MZ₃ ligand as a catalyst. A more rapid reaction is realizedby carrying out the preparation in an organonitrile solvent.

U.S. Pat. No. 4,416,825 also describes an improved, continuous processfor the preparation of hydrocyanation catalysts comprising zerovalentnickel complexes with monodentate organophosphorus compounds (ligands)by controlling the temperature of the reaction relative to the amount ofmonodentate ligand and conducting the reaction in the presence of achlorine ion and organic nitrile such as adiponitrile.

There are several processes that can be used to make nickel catalystcomplexes with phosphorous-containing ligands. One method is a reactionbetween nickel bis(1,5-cyclooctadiene) [NI(COD)₂] and a phosphiteligand; however, this process is not very economical because of the highcosts of Ni(COD)₂. Another process involves the in situ reduction ofanhydrous nickel chloride with zinc dust in the presence of thephosphite ligand. For this reaction to be successful, the nickel metalmust react with the phosphorous-containing ligand at a sufficient rateto produce the nickel complex.

U.S. Pat. No. 6,171,996 describes zero-valent nickel complexescomprising bidentate phosphite ligands prepared or generated accordingto techniques well known in the art, as described, for example, in U.S.Pat. Nos. 3,496,217; 3,631,191; 3,846,461; 3,847,959 and 3,903,120. Forexample, divalent nickel compounds may be combined with a reducingagent, to serve as a source of zero-valent nickel in the reaction.Suitable divalent nickel compounds are said to include compounds of theformula NiY₂ where Y is halide, carboxylate, or acetylacetonate.Suitable reducing agents are said to include metal borohydrides, metalaluminum hydrides, metal alkyls, Zn, Fe, Al, Na, or H₂. Elementalnickel, preferably nickel powder, when combined with a halogenatedcatalyst, as described in U.S. Pat. No. 3,903,120 is also a suitablesource of zero-valent nickel.

In comparison to monodentate phosphorus-containing ligands, bidentatephosphorus-containing ligands generally react more slowly with nickelmetals described in the above references. One example of a suitablenickel metal is the INCO type 123 nickel metal powder (Chemical AbstractService registry number 7440-02-0), derived from the decomposition ofnickel carbonyl at elevated temperatures.

Many nickel salts can be converted to nickel metal by reduction withhydrogen at elevated temperatures. Potential sources are nickel oxide,nickel formate, nickel oxalate, nickel hydroxide, nickel carbonate, andbasic nickel carbonate (BNC). BNC production has been disclosed by R. M.Mallya, et al. in the Journal of the Indian Institute of Science 1961,Vol. 43, pages 44-157 and M. A. Rhamdhani, et al., Metallurgical andMaterials Transactions B 2008, Vol. 39B, pages 218-233 and 234-245.

SUMMARY OF THE INVENTION

Bidentate ligands may be converted to nickel catalysts that have certainadvantages over the nickel catalysts comprising monodentate ligands,especially as olefin hydrocyanation catalysts. Unfortunately, the INCOtype 123 nickel metal powders have insufficient reactivity with the someof these bidentate ligands. Therefore, a nickel metal powder that issufficiently reactive with bidentate phosphorous ligands and methods ofmaking the nickel metal powder is desirable.

Basic nickel carbonate (BNC) is an inexpensive, commercially available,nickel source. However, evaluation of BNC samples from different minesand chemical vendors has revealed that different available BNC materialsgive rise to nickel metals with a wide range of reactivity withphosphorous-containing ligands to form nickel complexes.

The invention disclosed herein provides a basic nickel carbonate, whichyields a nickel metal that is highly reactive with both monodentate andbidentate phosphorous-containing ligands in forming nickel metalcomplexes. Also disclosed are methods of making the basic nickelcarbonate, since it has also been discovered that precipitationconditions for making the basic nickel carbonate influence the activityof the resulting nickel metal. The resulting nickel metal is useful informing nickel metal complexes for producing pentenenitriles anddinitriles by hydrocyanation.

In one aspect, a method of making a nickel-containing composition isdisclosed, comprising: (i) contacting a precipitant solution with anickel solution in a precipitation reactor to form a reaction mixture;and (ii) precipitating said nickel-containing composition from saidreaction mixture; wherein said nickel-containing solution comprisesnickel(II) ions and water and said precipitant solution is selected fromthe group consisting of: (a) bicarbonate ions and water, (b) carbonateions and water, and (c) mixtures thereof; and further wherein the moleratio of bicarbonate ions to nickel ions in the reaction mixture isbetween 0:1 to 2:1 and said mole ratio of carbonate ions to nickel ionsin the reaction mixture is between 0:1 to 1.6:1.

In a further aspect, the precipitant solution is added to the nickelsolution, for example, by gradual addition.

DETAILED DESCRIPTION Definitions

Monodentate: A single phosphorous atom that may bond to a single nickelatom to form the nickel complex.

Bidendate: Two phosphorous atoms that may bond to a single nickel atomto form the nickel complex.

Phosphite: An organophosphorous compound comprising a trivalentphosphorous atom bonded to three oxygen atoms.

Phosphonite: An organophosphorous compound comprising a trivalentphosphorous atom bonded to two oxygen atoms and one carbon atoms.

Phosphinite: An organophosphorous compound comprising a trivalentphosphorous atom bonded to one oxygen atoms and two carbon atoms.

Phosphine: An organophosphorous compounding comprising a trivalentphosphorous atom bonded to three carbon atoms.

Disclosed are novel nickel compositions, comprising nickel, and methodsof making the same. The nickel compositions can be made by contacting aprecipitant solution to a nickel solution in a precipitation reactor toform a reaction mixture; and (ii) precipitating said nickel compositionfrom said reaction mixture, wherein said nickel solution comprisesnickel(II) ions and water and said precipitant solution is selected fromthe group consisting of: (a) bicarbonate ions and water, (b) carbonateions and water, and (c) mixtures thereof. The mole ratio of bicarbonateions to nickel ions in the reaction mixture at the conclusion of saidfeeding can range from 0:1 to 2:1, including from about 0:1 to about1.6:1, from about 0:1 to about 1.2:1, from about 1.0:0 to about 1.9:1,from about 1.2:1 to about 1.9:1, from about 0.8:1 to about 1.4:1, fromabout 1.0:1 to about 1.8:1, from about 1.0:1 to about 1.6:1, from about1.0:1 to about 1.4:1, from about 0.8:1 to about 1.4:1, and from about0.8:1 to about 1.2:1. The mole ratio of carbonate ions to nickel ions inthe reaction mixture at the conclusion of said feeding can range from0:1 to 1.6:1, including from about 0:1 to about 1.4:1, from about 1.0:0to about 1.2:1, from about 0.8:1 to about 1.4:1, from about 1.0:1 toabout 1.6:1, from about 1.0:1 to about 1.6:1, from about 1.0:1 to about1.4:1, from about 0.8:1 to about 1.4:1, and from about 0.8:1 to about1.2:1. Blends of bicarbonates and carbonates can also be used in theprecipitant solution. As detailed more fully below, the molar ratio hasa surprising effect on the resulting nickel metal's effectiveness ofreacting with the phosphorous ligands.

The precipitation reactor may be any suitable containment vessel such asa tank or pipe. Further, the reaction mixture may be agitated prior toand/or during the precipitation of the nickel composition. For example,agitation may be done by mechanical stirring, pumped circulation loop,flow-through static mixture, or ultrasound. The nickel composition maybe precipitated within a temperature range of from about 0° C. to about90° C., including from about 20° C. to about 90° C., from about 20° C.to about 70° C., from about 20° C. to about 50° C., from about 50° C. toabout 90° C., from about 60° C. to about 80° C., and from about 65° C.to about 75° C. Furthermore, the nickel composition may be precipitatedfrom the reaction mixture in the presence of added carbon dioxide. Forexample, the carbon dioxide can be added to the precipitation reactor,added to the nickel solution, added to the precipitant solution, oradded to the reaction mixture, and any combination thereof. Also, theprecipitant solution may be fed over a period of from about 30 minutesto about 60 minutes, and can be done in a semi-continuous or continuousmanner. Further, the precipitant solution can be added to the nickelsolution in the precipitation reactor in a semi-continuous or continuousmanner, for example, gradual addition.

The reaction mixture may also be digested after contacting theprecipitant solution to the nickel solution by heating the reactionmixture from between about 50° C. and about 90° C. for a period of fromabout 0.25 hours to about 24 hours. Other suitable temperature rangesinclude from about 60° C. to about 80° C. and from about 65° C. to about75° C. Other suitable time periods can range from about 2 hours to about24 hours, including from about 4 hours to about 20 hours, from about 6hours to about 16 hours, and from about 8 hours to about 12 hours.

The disclosed nickel composition methods can further comprise, after theprecipitation step, washing the precipitated nickel composition withwater; and partially drying the precipitated nickel composition. Forexample, the precipitated nickel composition from the reaction mixtureis separated from the reaction mixture by filtration or decantation, theresulting precipitated nickel composition is washed with water byfiltration or decantation, and the resulting precipitated nickelcomposition is dried by water evaporation between 60° C. and 100° C.Drying can be performed under ambient pressure or under vacuum, and inthe presence of an inert gas such as nitrogen.

The nickel solution, comprising nickel(II) ions and water, may beprepared by dissolving a nickel(II) salt in water. The nickel salt canbe any salt that is soluble in water, for example NiCl₂, NiSO₄, andNi(NO₃)₂. The precipitant solution, comprising bicarbonate ions, may beprepared by dissolving a bicarbonate salt, for example, NaHCO₃ andNH₄HCO₃, in water or prepared in-situ by dissolving CO₂ and an alkalimetal hydroxide or ammonia in water by known methods. Likewise, theprecipitant solution, comprising carbonate ions, may be prepared bydissolving a carbonate salt, for example Na₂CO₃ or prepared in-situ bydissolving CO₂ and an alkali metal hydroxide in water by known methods.The anion of the nickel salt and cation of the bicarbonate or carbonatesalt may be selected such that a salt produced from the precipitation,comprising both the cation and anion from the reaction mixture (forexample NaCl), is soluble in the water of the reaction mixture. Such aselection provides a method for separating said salt product from theprecipitated nickel composition.

Also disclosed is a method of making a nickel-containing solidcomprising nickel metal. The method comprises: (i) providing the nickelcompositions disclosed above; and (ii) reducing at least a portion ofthe nickel composition of step (i) with a reducing agent to form anickel-containing solid, comprising nickel metal, wherein saidnickel-containing solid is adapted to effectively react with a bidendatephosphorous containing ligand to form a nickel complex of thephosphorous-containing ligand. The nickel-containing solid is morereactive with phosphorous-containing ligands than nickel-containingsolids made by other processes, such as INCO type 123 nickel metalpowder, nickel oxide, nickel formate, nickel oxalate, nickel hydroxide,nickel carbonate. The high reactivity is partially due to the BNCprocesses disclosed above, as well as the reducing process. The reducingagent can be hydrogen, carbon dioxide, carbon monoxide, methane,ammonia, hydrogen sulfide, merely to name a few nonlimiting examples ofsuitable reducing agents.

As previously stated, the amount of bicarbonate or carbonate ions fedrelative to the nickel(II) ions charged greatly affects the reactivityof the resulting nickel-containing solid with the phosphorous-containingligand to make a nickel complex. Because of the high costs of nickel,producers of BNC-type nickel compositions would be led to add excessamounts of the precipitant solution so as to recover as much of thenickel as economically feasible. However, it has been surprisingly foundthat the use of excess precipitant produces nickel metal of lowreactivity for the phosphorous-ligand complex reaction. Highly reactivenickel is produced when reduced levels of precipitant are used, andpresumably more of the nickel(II) ions are allowed to remain dissolvedin the water of the resulting reaction mixture.

It has also been found that the precipitated nickel composition madeusing bicarbonate ions filters and washes much faster than theprecipitated nickel composition made using carbonate ions. Also, thefiltered precipitated nickel composition made using bicarbonate ionsdries to a soft powder with little shrinkage. For these reasons,producing the nickel-containing solid using bicarbonate ions providesfurther desirable properties for downstream processing and handling ofthe dried precipitated nickel composition.

The reduction of the nickel composition with a reducing agent to form anickel-containing solid may be performed at a temperature in the rangefrom about 150° C. to about 700° C., including from about 300° C. toabout 500° C., and from about 350° C. to about 450° C. In anotheraspect, the reduction temperature is from about 350° C. to about 1500°C., including from about 350° C. to about 450° C. The reduction pressurecan range from about 0.01 atmospheres to about 100 atmospheres.Reduction may be carried out for a period of at least about 30 minutesusing a stoichiometric excess of a reducing agent, such as hydrogen,even though one mole of hydrogen per mole of nickel composition is thetheoretical and stoichiometric amount required for reduction. Forexample, the reducing period can be between about 1 to about 2 hoursusing a 2:1 mole ratio of hydrogen to nickel composition.

The disclosed nickel containing solids can be reacted with aphosphorous-containing ligand to make a nickel complex of thephosphorous-containing ligand. Such complexes are useful as a catalystprecursor for at least one of the following reactions: (1) reacting1,3-butadiene with hydrogen cyanide to produce 2-methyl-3-butenenitrileand 3-pentenenitrile; (2) reacting 2-methyl-3-butenenitrile to produce3-pentenenitrile; (3) reacting 3-pentenenitrile with hydrogen cyanide inthe presence of a Lewis acid to produce adiponitrile; and (4) reaction2-pentenenitrile with hydrogen cyanide in the presence of a Lewis acidto produce 3-pentenenitrile, 4-pentenenitrile, and adiponitrile.

The phosphorous-containing ligand may be a monodentate phosphite,mondentate phosphonite, monodentate phosphinite, monodentate phosphine,bidentate phosphite, bidentate phosphonite, bidentate phosphinite, orbidentate phosphine, and any combination of these members. Further, thephosphorous-containing ligand may be a monodentate phosphite to form thenickel complex of the monodentate phosphite then the nickel complex ofthe monodentate phosphite may be combined with a bidentatephosphorous-containing ligand. Likewise, the phosphorous-containingligand may be a bidentate phosphite further comprising a monodentatephosphite.

When the phosphorous-containing ligand is a bidentate phosphite, thebidentate phosphite may be selected from the members of the groupsconsisting of Formula Ia, Formula Ib, Formula Ic, or any combination ofthese members:

wherein in Formulae Ia, Ib, and Ic,R¹ is phenyl, unsubstituted or substituted with one or more C₁ to C₁₂alkyl, C₁ to C₁₂ alkoxy groups, or groups of Formulae A and B, or—(CH₂)_(n)OY²; or naphthyl, unsubstituted or substituted with one ormore C₁ to C₁₂ alkyl or C₁ to C₁₂ alkoxy groups, or groups of Formulae Aand B, or —(CH₂)_(n)OY²; or 5,6,7,8-tetrahydro-1-naphthyl;

wherein in Formulae A and B,Y¹ is independently selected from the group of H, C₁ to C₁₈ alkyl,cycloalkyl, or aryl, Y² is independently selected from the group of C₁to C₁₈ alkyl, cycloalkyl, or aryl, Y³ is independently selected from thegroup of O or CH₂, and n=1 to 4;wherein in Formulae Ia, Ib, and Ic,O—Z—O and O—Z¹—O are independently selected from the group consisting ofstructural Formulae II, III, IV, V, and VI:

wherein in Formulae II and III,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, and R⁹ are independently selected from thegroup consisting of H, C₁ to C₁₂ alkyl, and C₁ to C₁₂ alkoxy; X is O, S,or CH(R¹⁰);

R¹⁰ is H or C₁ to C₁₂ alkyl;

wherein in Formulae IV and V,R²⁰ and R³⁰ are independently selected from the group consisting of H,C₁ to C₁₂ alkyl, and C₁ to C₁₂ alkoxy, and CO₂R¹³;

R¹³ is C₁ to C₁₂ alkyl or C₆ to C₁₀ aryl, unsubstituted or substitutedwith C₁ to C₄ alkyl;

W is O, S, or CH(R¹⁴);

R¹⁴ is H or C₁ to C₁₂ alkyl;

and wherein in Formulae VI,R¹⁵ is selected from the group consisting of H, C₁ to C₁₂ alkyl, and C₁to C₁₂ alkoxy and CO₂R¹⁶; R¹⁶ is C₁ to C₁₂ alkyl or C₆ to C₁₀ aryl,unsubstituted or substituted with C₁ to C₄ alkyl.

When the phosphorus-containing ligand is a bidentate phosphite, thebidentate phosphite may be selected from the group consisting of FormulaVII and VIII,

wherein,

R⁴¹ and R⁴⁵ are independently selected from the group consisting of C₁to C₅ hydrocarbyl, and each of R⁴², R⁴³, R⁴⁴, R⁴⁶, R⁴⁷ and R⁴⁸ isindependently selected from the group consisting of H and C₁ to C₄hydrocarbyl;

orwherein the phosphorus-containing ligand is a bidentate phosphiteselected from the group consisting of Formula VII and VIII wherein,

R⁴¹ is methyl, ethyl, isopropyl or cyclopentyl;

R⁴² is H or methyl;

R⁴³ is H or a C₁ to C₄ hydrocarbyl;

R⁴⁴ is H or methyl;

R⁴⁵ is methyl, ethyl or isopropyl; and

R⁴⁶, R⁴⁷, R⁴⁸ and are independently selected from the group consistingof H and C₁ to C₄ hydrocarbyl;

wherein the phosphorus-containing ligand is a bidentate phosphiteselected from the group consisting of Formula VII and VIII wherein,

R⁴¹, R⁴⁴, and R⁴⁵ are methyl;

R⁴², R⁴⁶, R⁴⁷ and R⁴⁸ are H; and

R⁴³ is a C₁ to C₄ hydrocarbyl;

or

R⁴¹ is isopropyl;

R⁴² is H;

R⁴³ is a C₁ to C₄ hydrocarbyl;

R⁴⁴ is H or methyl;

R⁴⁵ is methyl or ethyl;

R⁴⁶ and R⁴⁸ are H or methyl; and

R⁴⁷ is H, methyl or tertiary-butyl;

wherein the phosphorus-containing ligand is a bidentate phosphiteselected from the group consisting of Formula VII and VIII wherein,

R⁴¹ is isopropyl or cyclopentyl;

R⁴⁵ is methyl or isopropyl; and

R⁴⁶, R⁴⁷, and R⁴⁸ are H;

and wherein the phosphorus-containing ligand is a bidentate phosphiteselected from the group consisting of Formula VII and VIII wherein, R⁴¹is isopropyl; R⁴², R⁴⁶, and R⁴⁸ are H; and R⁴³, R⁴⁴, R⁴⁵, and R⁴⁷ aremethyl.

Furthermore, when the phosphorus-containing ligand is a bidentatephosphite, the bidentate phosphite may be selected from the groupconsisting of Formula IX

wherein R¹⁷ is isopropyl, R¹⁸ is hydrogen, and R¹⁹ is methyl; andFormula X

wherein R¹⁷ is methyl, R¹⁸ is methyl, and R¹⁹ is hydrogen.

Additional bidendate ligands, ligand complexes, and methods of makingthe same, are disclosed in U.S. Pat. No. 6,171,996, herein incorporatedby reference in its entirety.

In any preceding method comprising reacting the nickel-containing solidwith a monodentate phosphorus-containing ligand, the reacting of thenickel-containing solid with the monodentate phosphorus-containingligand may further comprise at least one halogenated catalyst comprisinga phosphorus-halide bond selected from the group consisting of PX₃,R¹⁷PX₂, R¹⁸OPX₂, [R¹⁹][R²⁰]PX, [R²¹][R²²O]PX, and [R²³O][R²⁴O]PX;

wherein R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³, and R²⁴ are independentlyselected from the group consisting of C₁ to C₁₈ hydrocarbyl radicals andeach X is a halide independently selected from the group consisting ofchloride, bromide, and iodide

The bidentate phosphorous containing ligands can further comprise atleast one Lewis acid promoter. The Lewis acid may be selected from thegroup consisting of inorganic or organometallic compounds in which thecation is selected from the group including scandium, titanium,vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron,aluminum, yttrium, zirconium, niobium, molybdenum, cadmium, rhenium,lanthanum, europium, ytterbium, tantalum, samarium, and tin. Forexample, the at least one Lewis acid is selected from the groupconsisting of zinc chloride, ferrous chloride, or a combination of zincchloride and ferrous chloride.

The reaction between the nickel-containing solid and thephosphorous-containing ligand may further comprise an organonitrileselected from one or more members of the group consisting of2-pentenenitrile, 3-pentenenitrile, 4-pentenenitrile,2-methyl-3-butenenitrile, 2-methyl-2-bytenenitrile, adiponitrile,2-methylglutaronitrile, and ethylsuccinotrile.

Making the nickel complex or nickel complexes from the reaction ofmonodentate and bidentate ligands with the nickel-containing solids ofthis invention may be performed as described in U.S. Provisionalapplication No. 61/287,757 and the following Examples. For example, a 5wt % solution of a bidentate phosphorus-containing ligand inpentenenitrile solvent further comprising a Lewis acid like ZnCl₂ (0.5to 2.5 moles Lewis acid per mole bidentate phosphorus-containing ligand)is contacted with the nickel-containing solid of the invention (forexample, 4.0 wt % nickel-containing solid). Temperatures between 60° C.and 80° C. give acceptable reaction rates. Sufficient agitation may beused to suspend the nickel-containing solid in this reaction mixture.

EXAMPLES Definitions of Abbreviations

ADN=adiponitrile; BD=1,3-butadiene; hrs=hours; BNC=basic nickelcarbonate; 2M3BN=2-methyl-3-butenenitrile; MGN=2-methylglutaronitrile;pentenenitrile or pentenenitriles=4PN, 3PN, 2PN, 2M3BN, and 2M2BNisomers unless specifically limited; 2PN=2-pentenenitrile including bothc2PN and t2PN isomers unless specifically limited; 3PN=3-pentenenitrileincluding both c3PN and t3PN unless specifically limited;4PN=4-pentenenitrile; ppm=parts per million by weight; wt %=% by weight.

Various aspects of the disclosed BNC compositions, nickel-containingsolids, phosphorous-containing nickel metal complexes, and methods ofmaking the same may be further understood in view of the followingnon-limiting examples. In the following paragraphs, all references areincorporated herein by reference.

Bidentate Phosphorus-Containing Ligand

Examples 1 to 13 use a bidentate phosphite ligand, Ligand A. Ligand Amay be prepared by any suitable synthetic means known in the art. Forexample, 3,3′-diisopropyl-5,5′,6,6′-tetramethyl-2,2′-biphenol can beprepared by the procedure disclosed in U.S. Published patent applicationNo. 2003/0100802 in which 4-methylthymol can undergo oxidative couplingto the substituted biphenol in the presence of a copperchlorohydroxide-TMEDA complex (TMEDA isN,N,N′,N′-tetramethylethylenediamine) and air. The phosphorochloriditeof 2,4-xylenol, [(CH₃)₂C₆H₃O]₂PCl, can be prepared, for example, by theprocedure disclosed in U.S. Published patent application No.2004/0106815. To selectively form this phosphorochloridite, anhydroustriethylamine and 2,4-xylenol can be added separately and concurrentlyin a controlled manner to PCl₃ dissolved in an appropriate solvent undertemperature-controlled conditions. The reaction of thisphosphorochloridite with the3,3′-diisopropyl-5,5′,6,6′-tetramethyl-2,2′-biphenol to form the desiredLigand A can be performed, for example, according to the methoddisclosed in U.S. Pat. No. 6,069,267, herein incorporated by reference.The phosphorochloridite can be reacted with3,3′-diisopropyl-5,5′,6,6′-tetramethyl-2,2′-biphenol in the presence ofan organic base to form Ligand A, which can be isolated according totechniques well known in the art, for example as also described in U.S.Pat. No. 6,069,267. Ligand A is an example of a compound of Formula Iand the Ligand A solutions in 3PN solvent below do not contain anyhalogenated catalysts of U.S. Pat. No. 3,903,120.

Example 16 uses a mixture of different monodentate phosphites, Ligand B,that is derived from the reaction of a m-cresol/p-cresol/phenol mixturewith PCl₃. Ligand B is an example of a compound of Formula II.

[m-(CH₃)C₆H₄O]_(x) [p-(CH₃)C₆H₄O]_(y)(C₆H₅O)_(z)P

Ligand B

wherein x+y+z=3.

Example 1

A 1 molar NiCl₂ solution (250 mL, 0.25 mole NiCl₂) in water is chargedto a 1 liter beaker then this solution is magnetically stirred withheating to 70° C. While maintaining this temperature, a precipitantsolution comprising bicarbonate ions (25.2 gm of NaHCO₃ dissolved in 400mL water, 0.30 mole NaHCO₃) is fed continuously into the beaker at arate of 10 mL/min as the reaction mixture is sparged with added CO₂ gasat a rate of 100 mL/min. At the conclusion of the precipitant solutionaddition, the total moles of bicarbonate ions fed per mole of nickelions charged is 1.2:1. This addition causes a solid product, a BNCcomposition comprising nickel, to precipitate from the reaction mixture.After all the precipitant solution is added, the flow of carbon dioxidegas to the reaction mixture is then terminated and the resultingreaction mixture slurry is then allowed to digest for 2 hours at 70° C.At the conclusion of this digestion period, this slurry is then filteredusing a sintered glass filter, and the solid filter cake is displacementwashed with 200 mL water. The solid filter cake is then dried in avacuum oven at 80° C. overnight while sweeping nitrogen through thevacuum oven.

Fifteen grams of the dried solid filter cake is then placed inside areaction tube that can be heated within an electrical furnace located ina lab fume hood. Hydrogen gas flow to the reaction tube is then set at0.2 liters/minute (about one atmosphere) with any hydrogen off gas fromthe reaction tube flowing through a bubbler. The temperature of the tubefurnace is then increased at a rate of 10° C./minute to a finaltemperature of 400° C., and then held for one hour at 400° C., afterwhich the reaction tube is allowed to cool under hydrogen flow. Afterthe reaction tube temperature falls below 50° C. the flow to thereaction tube is switched to nitrogen gas to purge the hydrogen from thereaction tube. Valves on the reaction tube were then closed to preventexposure of the resulting nickel-containing solid, comprising nickelmetal, to air, and the entire reaction tube is transferred to anitrogen-filled dry lab and the nickel-containing solid emptied into abottle. This nickel-containing solid contains nickel metal as it isattracted to magnets. Exposing these nickel-containing solids to air canreduce rates for the following reaction and/or cause thenickel-containing solids to burn in air to form nickel oxide.

Nickel complexes are also prepared in this nitrogen-filled dry lab byplacing 3.2 gm of this nickel-containing solid, 80 gm of a 5 wt % LigandA solution in 3PN, and 0.50 gm of anhydrous ZnCl₂, into a bottle reactorthat contained a magnetic stir bar. The nickel-containing solid is notsoluble in this reaction mixture. With magnetic stirring, the reactionmixture is then heated rapidly to 80° C., and a filtered sample iswithdrawn from this reaction mixture after 30 minutes and is found tocontain 1460 ppm nickel, according to a UV-visible or LC analysis, asnickel complexes of Ligand A dissolved in the 3PN. For example, acalibrated absorption method that detects the soluble divalent nickelcomplex (Ligand A)Ni(η³-C₄H₇)C≡N—ZnCl₂ by the amount of absorption at awavelength of 380 nanometers is used. This absorption method iscalibrated against a LC analysis for total soluble nickel.

Examples 2 to 5

The general procedure of Example 1 is repeated in Examples 2 to 5,except that the total moles of bicarbonate ions fed per mole of nickelions charged is varied from 1.6:1 to 2.0:1 by adjusting the amount ofNaHCO₃ dissolved in the 400 mL water to prepare the precipitantsolution. Results from the reaction of the resulting nickel-containingsolids with the Ligand A solution and ZnCl₂ are provided in Table 1.

TABLE 1 Effect of the First Molar Ratio, Moles Bicarbonate Ions Fed/MoleNickel Ions Charged, on the Reaction of the Resulting Nickel-ContainingSolid with Ligand A and ZnCl₂ to Produce Nickel Complexes of Ligand A.Moles HCO3 Precipitant Solution Ions Fed/Mole Example gm NaHCO3 moleNaHCO3 Ni Ions Charged ppm Ni* 1 25.2 0.30 1.2 1460 2 33.6 0.40 1.6 13903 37.8 0.45 1.8 1060 4 39.3 0.47 1.9 823 5 42.0 0.50 2.0 92 *As nickelcomplexes of Ligand A dissolved in the 3PN.

Examples 1 through 5 illustrate that as the amount of bicarbonate ionsfed is increased relative to the nickel ions charged, there is a declinein the reactivity of the resulting nickel-containing solid with aphosphorus-containing ligand to form soluble nickel complexes. That is,greater amounts of nickel complexes are formed when this first molarratio, moles bicarbonate ions fed/mole nickel ions charged, is between0.0:1 and 2.0:1.

Example 6

Example 2 is repeated except in the absence of sparging CO₂ gas throughthe reaction mixture during the feeding of the sodium bicarbonatesolution to the 1 liter beaker comprising the nickel ions. As shown inTable 2, greater amounts of nickel complexes are formed from thereaction of the resulting nickel-containing solid with the Ligand Asolution and ZnCl₂ when the solid product precipitates in the presenceof added CO₂ gas.

TABLE 2 Effect of the Presence of Added CO₂ Gas During the Precipitationof the Solid Product on the Reaction of the Resulting Nickel-ContainingSolid with Ligand A and ZnCl₂ to Produce Nickel Complexes of Ligand A.Moles HCO3 Precipitant Solution Ions Fed/Mole Example gm NaHCO3 moleNaHCO3 Ni Ions Charged ppm Ni* 2 33.6 0.40 1.6 1390 6 33.6 0.40 1.6 965*As nickel complexes of Ligand A dissolved in the 3PN.

Examples 7 and 8

Example 2 is repeated except that temperatures of the heated NiCl₂solution, reaction mixture during continuous feeding of the precipitantsolution to the 1 liter beaker, and digestion period are 50° C. forExample 7 and 90° C. for Example 8. In comparison to Example 2 (seeTable 3), greater amounts of nickel complexes are formed from thereaction of the resulting nickel-containing solid with the Ligand Asolution and ZnCl₂ when the solid product precipitates at 70° C. ratherthan 50° C. or 90° C.

TABLE 3 Effect of Precipitation Temperature on the Reaction of theResulting Nickel-Containing Solid with Ligand A and ZnCl₂ to ProduceNickel Complexes of Ligand A. Heated NiCl₂ Digestion Example SolutionReaction Mixture Period ppm Ni* 2 70° C. 70° C. 70° C. 1390 7 50° C. 50°C. 50° C. 845 8 90° C. 90° C. 90° C. 850 *As nickel complexes of LigandA dissolved in the 3PN according to an analysis.

Example 9

Example 2 is repeated except substituting NiSO₄ for NiCl₂. That is,continuously feeding the precipitant solution of Example 2 to a 1 molarNiSO₄ solution (250 mL, 0.25 mole NiSO₄) in water at 70° C. Similar tosolid product precipitated from NiCl₂, equivalent amounts of nickelcomplexes are formed (1465 ppm nickel) after 30 minutes from thereaction of the resulting nickel-containing solid with the Ligand Asolution and ZnCl₂ when the solid product precipitates from the NiSO₄solution.

Example 10

A 1 molar NiSO₄ solution (250 mL, 0.25 mole NiSO₄) in water is chargedto a 1 liter beaker then this solution is magnetically stirred withheating to 70° C. While maintaining this temperature, a precipitantsolution comprising carbonate ions (21.2 gm of Na₂CO₃ dissolved in 400mL water, 0.20 mole Na₂CO₃) is fed continuously into the beaker at arate of 10 mL/min but no CO₂ gas is sparged into the reaction mixture.At the conclusion of the precipitant solution addition, the total molesof carbonate ions fed per mole of nickel ions charged is 0.8. Thisaddition also causes a solid product to precipitate from the reactionmixture. After all the precipitant solution is added, the resultingreaction mixture slurry is then allowed to digest for 2 hours at 70° C.At the conclusion of this digestion period, this slurry is then filteredusing a sintered glass filter, and the solid filter cake is displacementwashed with 200 mL water. The solid filter cake is then dried in avacuum oven at 80° C. while sweeping nitrogen through the vacuum ovenovernight.

Fifteen grams of the dried solid filter cake is reduced with hydrogenflow at elevated temperatures as described in Example 1. Nickelcomplexes are also prepared as described in Example 1. A filtered sampleis withdrawn from the reaction mixture in the bottle reactor after 30minutes and is found to contain 1420 ppm nickel, according to aUV-Visible or LC analysis, as nickel complexes of Ligand A dissolved inthe 3PN.

Examples 11 to 13

The general procedure of Example 10 is repeated in Examples 11 to 13.The difference being that the total moles of carbonate ions fed per moleof nickel ions charged is varied from 1.0:1 to 1.6:1 by adjusting theamount of Na₂CO₃ dissolved in the 400 mL water to prepare theprecipitant solution. Results from the reaction of the resultingnickel-containing solids with the Ligand A solution and ZnCl₂ areprovided in Table 4.

TABLE 4 Effect of the Second Molar Ratio, Moles Carbonate Ions Fed/MoleNickel Ions Charged, on the Reaction of the Resulting Nickel-ContainingSolid with Ligand A and ZnCl₂ to Produce Nickel Complexes of Ligand A.Moles CO3 Precipitant Solution Ions Fed/Mole Example gm Na2CO3 moleNa2CO3 Ni Ions Charged ppm Ni* 10 21.2 0.20 0.8 1420 11 26.5 0.25 1.01340 12 31.8 0.30 1.2 1065 13 42.0 0.40 1.6 0 *As nickel complexes ofLigand A dissolved in the 3PN.

Examples 10 through 13 illustrate that the reactivity of the resultingnickel-containing solid with a phosphorus-containing ligand to formsoluble nickel complexes can decline as the amount of carbonate ions fedis increased relative to the nickel ions charged. That is, greateramounts of nickel complexes are formed when this second molar ratio,moles carbonate ions fed/mole nickel ions charged, is between 0.0:1 and1.6:1.

Example 14

Example 5 is repeated except that the order of addition is reversed forthe solid precipitation reaction in the 1 liter beaker. That is, the 1molar NiCl₂ solution is added to the precipitant solution to precipitatea solid product. After digestion, filtration, displacement washing,drying, reducing with hydrogen gas in the reactor tube at 400° C.,followed by reacting the resulting nickel-containing solid with theLigand A solution in 3PN and ZnCl₂, the filtered sample withdrawn fromthe reaction mixture is found to contain 0 ppm nickel as nickelcomplexes of Ligand A dissolved in the 3PN.

Example 15

At a constant precipitation temperature, the weight of the dried solidfilter cake is also a function of the total moles of bicarbonate(Examples 1 to 9, Table 5) or carbonate ions (Examples 10 to 13, Table6) fed per mole of nickel ions charged.

TABLE 5 Effect of the First Molar Ratio, Moles Bicarbonate Ions Fed/MoleNickel Ions Charged, on the Weight of the Dried Solid Filter Cake andReaction of the Resulting Nickel-Containing Solid with Ligand A andZnCl₂ to Produce Nickel Complexes of Ligand A. Example 1 2 6 7 8 9 3 4 514 Precipiating 70° C. 70° C. 70° C. 50° C. 90° C. 70° C. 70° C. 70° C.70° C. 70° C. Temperature Moles HCO3 Ions 1.2 1.6 1.6 1.6 1.6 1.6 1.81.9 2.0 2.0 Fed/Mole Ni Ions Charged gm Dried Solid 16.2 21.70 22.1 22.315.9 23.5 24.2 26.8 27.6 26.2 Filter Cake ppm Ni* 1460 1390 965 845 8501465 1060 823 92 0

TABLE 6 Effect of the Second Molar Ratio, Moles Carbonate Ions Fed/MoleNickel Ions Charged, on the Weight of the Dried Solid Filter Cake andReaction of the Resulting Nickel-Containing Solid with Ligand A andZnCl₂ to Produce Nickel Complexes of Ligand A. Example 10 11 12 13 MolesCO3 Ions Fed/Mole Ni Ions 0.8 1.00 1.2 1.6 Charged gm Dried Solid FilterCake 23.6 26.70 28.7 32.7 ppm Ni* 1420 1340 1065 0 *As nickel complexesof Ligand A dissolved in the 3PN.

Also, it is generally observed that times required for the filtration ofthe precipitated solid product and displacement wash of the solid filtercake, as described in Examples 1 to 14, are greater when the solidproduct is precipitated using carbonate ions in comparison to usingbicarbonate ions. For example at equivalent filtration conditions, thefiltration time is 14 minutes and the displacement wash time is 40minutes for the solid product of Example 11 that is precipitated withcarbonate ions. But for the solid product precipitated with bicarbonateions, the filtration time and displacement wash time can both be lessthan 1 minute each.

Example 16

The nickel-containing solids of Examples 1 to 13 are reacted with themonodentate phosphite Ligand B in 3PN solvent to form nickel complexes,comprising zero-valent nickel and Ligand B, in the absence of a Lewisacid such as ZnCl₂.

Example 17

ZnCl₂ is at least partially separated from the nickel complex ofExamples 1 to 12 then the nickel complex of Ligand A contacts BD andHC≡N in a reaction zone. A catalyst forms to produce 3PN, 2M3BN, or acombination thereof. The same nickel complexes also react with 2M3BN toproduce 3PN.

Nickel complexes of Ligand B of Example 16 contact HC≡N and BD in areaction zone. A catalyst forms to produce 3PN, 2M3BN, or a combinationthereof. The same nickel complexes also react with 2M3BN to produce 3PN.

In the presence of a Lewis acid promoter, like ZnCl₂, the soluble nickelcomplexes of Ligand A from bottle reactors of Examples 1 to 12 contactHC≡N and 3PN in a reaction zone. A catalyst forms converting greaterthan 90% of the 3PN to dinitriles comprising ADN, MGN, and ESN, with anADN distribution of 95-96%. The ADN distribution equals 100%*wt %ADN/(wt % ADN+wt % MGN+wt % ESN), as determined by gas chromatography(GC).

In the presence of a Lewis acid promoter, like ZnCl₂, the soluble nickelcomplexes of Ligand A from bottle reactors of Examples 1 to 12 contactHC≡N and 2PN in a reaction zone. A catalyst forms converting a portionof the 2PN to 3PN, 4PN, and ADN.

In the presence of a Lewis acid promoter, like ZnCl₂, triphenylboron, orcompounds of the chemical formula [Ni(C₄H₇C≡N)₆][(C₆H₅)₃BC≡NB(C₆H₅)₃]₂as disclosed in U.S. Pat. No. 4,749,801, the nickel complexes of Example16 contact HC≡N and 3PN in a reaction zone. A catalyst forms converting3PN to dinitriles comprising ADN, MGN, and ESN, wherein ADN is the majordinitrile product.

The invention has been described above with reference to the variousaspects of the disclosed nickel compositions, basic nickel carbonates,and methods of making the same. Obvious modifications and alterationswill occur to others upon reading and understanding the proceedingdetailed description. It is intended that the invention be construed asincluding all such modifications and alterations insofar as they comewithin the scope of the claims.

1. A method of making a nickel-containing composition comprising a.contacting a precipitant solution with a nickel solution in aprecipitation reactor to form a reaction mixture; and b. precipitatingsaid nickel-containing composition from said reaction mixture; whereinsaid nickel solution comprises nickel(II) ions and water and saidprecipitant solution is selected from the group consisting of: (i)bicarbonate ions and water, (ii) carbonate ions and water, and (c)mixtures thereof; and further wherein the mole ratio of bicarbonate ionsto nickel ions in the reaction mixture is between 0:1 to 2:1 and saidmole ratio of carbonate ions to nickel ions in the reaction mixture isbetween 0:1 to 1.6:1.
 2. The method of claim 1 wherein the contacting(a) comprises adding the precipitant solution to the nickel solution. 3.The method of claim 1, wherein said nickel(II) ions are selected fromthe group consisting of NiCl₂, NiSO₄, and Ni(NO₃)₂.
 4. The method ofclaim 2, wherein said nickel(II) ions are selected from the groupconsisting of NiCl₂, NiSO₄, and Ni(NO₃)₂.
 5. The method of claim 3,wherein said nickel(II) ions are NiCl₂.
 6. The method of claim 4,wherein said nickel(II) ions are NiCl₂.
 7. The method of claim 1 or 2,wherein said bicarbonate ions are selected from the group consisting of:NaHCO₃ and NH₄HCO₃.
 8. The method of claim 1 or 2, wherein saidcarbonate ions comprise Na₂CO₃.
 9. The method of claim 1 or 2 furthercomprising contacting said reaction mixture with carbon dioxide.
 10. Themethod of claim 9, wherein said contacting is performed whileprecipitating said nickel composition.
 11. The method of one of claims1-6 further comprising digesting the reaction mixture prior toprecipitating said nickel composition.
 12. The method of claim 11,wherein said digestion is performed at a temperature from about 50° C.to about 90° C. and a duration from about 0.25 hours to about 24 hours.13. The method of one of claims 1-6, wherein said precipitating saidnickel composition is performed at a temperature of from about 0° C. toabout 90° C.
 14. The method of claim 13, wherein said temperature isfrom about 50° C. to about 90° C.
 15. The method of claim 14, whereinsaid temperature is from about 65° C. to about 75° C.
 16. The method ofone of claims 1-6, wherein said mole ratio of bicarbonate ions to nickelions can be selected from the group consisting of: from about 0:1 toabout 1.6:1, from about 0:1 to about 1.2:1, from about 1.0:0 to about1.9:1, from about 0.8:1 to about 1.4:1, from about 1.0:1 to about 1.8:1,from about 1.0:1 to about 1.6:1, from about 1.0:1 to about 1.4:1, fromabout 0.8:1 to about 1.4:1, and from about 0.8:1 to about 1.2:1.
 17. Themethod of one of claims 1-6, wherein said mole ratio of carbonate ionsto nickel ions can be selected from the group consisting of: from about0:1 to about 1.4:1, from about 1.0:0 to about 1.2:1, from about 0.8:1 toabout 1.4:1, from about 1.0:1 to about 1.6:1, from about 1.0:1 to about1.6:1, from about 1.0:1 to about 1.4:1, from about 0.8:1 to about 1.4:1,and from about 0.8:1 to about 1.2:1.
 18. The method of claim 16, whereinsaid bicarbonate ions are selected from the group consisting of: NaHCO₃and NH₄HCO₃.
 19. The method of claim 17, wherein said carbonate ionscomprise Na₂CO₃.
 20. The method of one of claims 1-6 further comprising(c) washing said precipitated nickel composition with water; and (d)partially drying the precipitated nickel composition.